The role of adult supervision in childhood injuries has not been well studied. Parental supervision is an important determinant of child safety and inadequate supervision is often cited as a risk factor for childhood injury. Objectives: For children less than age five seeking medical care for an acute, unintentional injury, the two primary aims of this project are to: 1) classify patterns of supervision: a) along three dimensions: proximity (e.g., within reach, beyond reach), attention (e.g., visual, auditory), and continuity (e.g., constant, intermittent), b) combine the dimensions to create a composite score representing a range of supervision vigilance and explore the relationships between different supervision dimensions, vigilance and severity of injury;and 2) conduct case-crossover analyses to determine if an association exists between supervision and unintentional injury. A third, exploratory aim is to: 3) explore the relationships between specific child characteristics, parent characteristics, and social context factors and supervision patterns. Design: A case-crossover study. In the case-crossover design, case and control data are obtained on the same person. This methodology permits the assessment of risk factors for an acute event (injury) while controlling for stable person-specific factors (e.g., socio-economic status, age, sex, risk taking behavior). Setting: Two sites will be used for subject recruitment: 1) the Emergency Department (ED) and Trauma Service of the University of Missouri Hospital, a Level I Trauma Center located in Columbia, MO., and 2) the Trauma Service of the Children's Mercy Hospital, a Level I Pediatric Trauma Center located in urban Kansas City, MO. Participants: The caregiver(s) of approximately 230 children less than age five with an acute, unintentional injury seeking care at one of the study sites. Analysis: Correlations will be used to explore relationships in Aim 1. Conditional logistic regression will be used to calculate adjusted odds ratios and 95 percent confidence intervals for the association between supervision and injury in Aim 2. Multiple regression will be used to explore relationships in Aim 3. Significance: The results will reveal important information on relationships among the complex, multiple risk factors for injuries in young children and lay the groundwork for a large scale study that will include recruitment of an uninjured comparison group. PUBLIC HEALTH RELEVANCE: This research program will provide critical information for further advancing the field of childhood injury prevention. Despite advances in prevention over the past 25 years, injuries remain the leading cause of death and a significant cause of morbidity among children age one year and older in the United States. Behavioral factors, and supervision in particular, have not been adequately studied. The proposed study will fill an important gap in our knowledge of the role of adult supervision in childhood injuries and will provide essential information necessary to develop effective injury prevention strategies and reduce the burden of injury for our most vulnerable population: young children.